A large number of commercial and factory or plant roofs are of a flat roof design wherein the roofing material itself is often of built-up asphalt and, in more modern systems, of a single ply EPDM elastomeric sheet or membrane. In terms of securing a single ply EPDM membrane to the roof itself, one common design utilized is the mechanical ballast system that uses a layer of stone over the membrane. While the ballast system is least expensive, it has the disadvantage of being quite heavy (about 10 lbs. per square foot) thus requiring a heavy roof support structure and, in addition, the roof slope cannot exceed 10.degree..
Adhered roof membrane retention systems suffer from a cost penalty while mechanical fastening systems generally require a fixation to the roof substrate by metal fasteners with metal or rubberized nailing strips. Additional sealing strips or caps are then required to keep the punctured membrane water tight. Such installations are cumbersome as well as time-consuming in addition to violating the integrity of the membrane itself.
Copending U.S. Application Ser. No. 516,522 to Yang, et al., filed July 25, 1983 and assigned to common assignee, discloses a mechanical fastening system for securing a flexible sheet within a channel member via an insert member wherein the latter is made of flexible resilient material having a central longitudinal flex notch that serves to define two adjacent wing portions and permits a temporary elastic deformation of the insert member into an inverted V-shape for insertion of the insert member, together with adjacent portions of the flexible sheet, into the channel member. In the interest of full disclosure, the previously-noted application is incorporated herein by reference to the extent necessary to explain this particular mechanical fastening system.
The prior art construction set forth in U.S. Pat. No. 3,532,032 to Weber discloses a machine for sealing joints comprising a handlebar assembly attached to a yoke which comprises a series of parallel bars. The bars, in turn, attach to a pressure wheel located behind a series of opposed roller elements. The tool is used for transversely compressing a sealing strip and then placing the strip inside a channel. A handled portion can be attached to rubber wheels or can be positioned over a first set of wheels. Rollers are mounted on compressor plates which are mutually angled in order that the sealing strip is gradually compressed when passing between the rollers.
U.S. Pat. No. 2,025,449 to Heltzel discloses a machine for placing a strip between pavement slabs. The apparatus comprises a U-shaped channel member which is placed inside wet concrete; a blade portion which is mounted within the channel portion; a pair of grooved folding discs having substantially concave circumferences which are mounted on top of the blade; and a strip made of an appropriate material which is oriented to be deposited within the concrete. In operation, the strip is fed over the inclined edge of the blade whereupon it is contacted by grooved folding disc and folded into an inverted V-shape. The strip of the material than passes over the blade where it is then inserted into the concrete at the end of the blade to form a sealing joint member. As shown in FIG. 11, in a further embodiment, a rotary disc is used to compress and shape the strip in the concrete.
U.S. Pat. No. 1,997,216 to Heltzel in FIG. 16 discloses a compressing tool attached to a substantially U-shaped frame which in turn attaches to a tubular handle. A disc is rolled between guide blades such that it will cut a groove in concrete and depress the joint strip into the groove.
U.S. Pat. No. 2,045,256 to Voigt, et al. discloses a machine for compressing a pre-formed strip and placing the strip within a joint. As shown in FIG. 7, the machine comprises a reel portion mounted on top of a frame for feeding the rolling strip through inclined discs such that the strip is decreased along its transverse width. The strip is then pressurized by means of an air hammer such that it will be placed downward into the joint in an appropriate position. Located on either side of the discs are a pair of bevelled rollers which contact each side of the discs in order to compress the space between the discs.
U.S. Pat. No. 3,364,828 to Shope, et al. discloses a strip inserting apparatus to compress and place a strip between paving sections wherein the apparatus comprises a pair of parallel side members relative to which are mounted a set of opposed rollers. Located behind the rollers is a compression disc which has a V-shaped circumferential cross section that substantially places and pushes the strip into a joint.
U.S. Pat. No. 3,395,627 to Barton discloses a sealing-strip placing apparatus comprising a tubular portion which is attached to a handle portion. At the mid-point of the tubular portion are a pair of axles which extend from a central joint to support wheels. The strip material is supported on a roller wheel which is attached to the handlebar in order that the material can be transported and placed into the channel. To accomplish this, the material is fed through a lubricator box which contains a pair of substantially opposed rollers disposed at angles relative to one another such that the strip is pressed into a V-shape. However, the strip is placed into the joint by means of a tube which extends below the cart into the joint.